Aryl esters of nitro amino benzene sulphonic acids



Patented Oct. 25, 1927.

UNITE ST AT PA orl-"lcs.

WALTER DUISBERG, OF LEVERKUSEN, NEAR COLOGNE, AND WINFBID HENTRIGH AND LUDWIG ZEH, OF WIESDORF, NEAR COLOGNE, GERMANY, ASSIG-NORS T GBASSELLI DYESTUFF CORPORATION, OF NEW YORK, N. 2., A. CORPORATION OF DELAWARE.

ARYL ESTERS 0F NITRO AMINO BENZENE SULIPHONIU ACIDS.

No Drawing. Application filed June 9, 1925, Serial No. 36,042, and in Germany June 14, 1824.

Our invention resides in the hitherto unknown arylesters of nltro-amlnobcnzene sulphonic acids of the general formula and in the process ofproducing these new compounds. In the above formula R stands for a radical of the benzene or naphthalene 0 series in which one or more of the hydrogens of the benzene or naphthalene nucleus may be substituted by methyl, ethyl, carboxyl, or

dialkylamino groups or halogen atoms,

etc. R is, therefore, equivalent to (Ll-l 5 cam unseat. c n i L O i w SM O i QO H etc.

Our new process in the preferred embodiment comprises the following steps. A n1- tro-halogenobenzene sulphochloride 1s first condensed in alkaline solution with an equivalent amount of phenol or naphthol or a nuclear substitution product thereof, 1. e, a hydroxy aryl compound, the aryl nucleus of which contains not more than ten carbon atoms 1 In this formula Ha stands for a halogen atom and R stands for a radical of the benzone or naphthalene series or a nuclear substitution product thereof. Th s reaction proceeds rapidly in aqueous medium at slightly elevated temperature. The phenolate or naphtholate reacts practically exclusively with the chlorine atom of the sulphochloride. The nitro-halogenobenzene 'sulphonic acid 40 arylesters formed are then treated with aqueone or alcoholic ammonia at elevated and eventually super-atmospheric pressure whereby the halogen atom is replaced by the amino group.

and the nitro-aminobenzene sulphonic acid arylester is formed. In the above formula Ha stands for a halogen atom and R stands for a radical of the benzene or naphthalene series or a nuclear substitution product thereof. Under these conditions the reaction is practically quantitative, no substantial amounts of the arylester being saponified.

The new nitro-aminobenzene sulphonic acid arylesters are usually slightly colored crystalline bodies, melting without decomposition. They are practically insoluble in water, but soluble in most organic solvents. They show the typical reactions of nitro and amino compounds. They are valuable intermediates for the production of dyestufi's.

The process as illustrated in the following examples can be varied within wide limits without departing from the spirit of our invention; optimum concentrations, times, tent peratures, times of reaction, etc. depend on the individual properties of the ingredients and starting materials used. The parts given are by weight.

Example ].255 parts of 100% 4c-nitro-l chlorobenzene-Q-sulphochloride are gradually introduced at 90 C. with violent stirring into a Water solution of 116 parts sodium phenolate. The reaction is complete after about 1 hours stirring, the solution shows then only a faint alkaline reaction. On cooling a yellowish-white oil separates completely. Dissolved in hot alcohol ,it is obtamed' on cooling as large colorless,

prismatic crystals. melting at 92.5-93.5 G. (uncorrected). It is the 4-nitro-1-chlorobenzene-SZ-sulphonic acid phenylester, having most probably the formula i 4 nitro 1 aminobenzene-2-sulphonic hot water. The residue consists of thg acl phenylester, having most probably the formula lit is practically insoluble in water, but soluble 1n the usual organic solvents. It is obtained in a pure state by recr stallization from benzene as clusters of ye low needles melting at 112.5113.5 C. (uncorrected) lit shows the usual reactions of nitro and amino groups, as for instance reduction, reaction with acids to form salts, reaction with nitrous acid to form a diazo compound, etc.

Example .Q.255 parts of 2-nitro-1-chlorobenzene-4-sulphochloride are slowl added to a water solution of 130 parts so ium para cresolate, keeping the temperature at 90 C. The reaction proceeds rapidly; after completion the 2-nitro-1-chlorobenzene-4 sulphonic acid para-cresylester, having most probably the formula 0 mOom separates as a heavy oily substance. By recrystallization from alcohol it is obtained as colorless needles a gregated into clusters, It melts at 6768 (uncorrected). 100 parts of this ester are suspended in 400 parts alcoholic ammonia and heated in an autoclave for several hours to IOU-120 C. After completion of the reaction the solvent is distilled 0E and the residue extracted with hot water to eliminate the ammonium chloride formed. The 2 nitro 1 aminobenzene-4- cresylester.

m-o-O-om After cooling the t-nitro-l-chlorobenzene-2- sulphonic acid 2-methoxyphenyl ester separates as a fine crystalline powder. it melts at 83-8t C. (uncorrected) and has most probably the formula Bot-0Q w parts of this ester are treated for several hours in an autoclave with 320 parts concen trated aqua ammonia at anextcrnal temperature of 120-130" C. The reaction mass is evaporated to dryness and the remaining residue extracted with hot water. The soobtained a-nitro-l-aminobenzene-Q-sulphonic acid o-methoxyphenylester NHa can be recrystallized from a benzene-petrolether mixture, it is then obtained as a yellow crystalline powder, melting at 133-134 G. (uncorrected). It is for all practical pur poses insoluble in water but soluble in the usual organic solvents. It shows all the reactions inherent to compounds containing nitro and amino groups, such as reduction of the nitro group to an amino group, diazotization of the amino group, etc.

We claim:

- 1. In processes of producing nitro-aminobenzene sulphonic acid arylesters the steps comprising reacting in alkaline solution with a gydroxy-aryl compound, the aryl nucleus 0 which contains not more than ten carbon atoms upon a nitro-halogenobenzene sulphochloride to'produce a nitro-halogenobenzene sulphonic acid arylester, reacting with ammonia upon such nitro-halog'enobenzene sulphonic acid arylester to efiectthe replacement of the halogen by the amino oup and recovering the nitro-aminoenzene sulphonicacid arylester formed.

2. In processes of producing nitro-aaninobenzene sulphonic acid arylesters the steps comprising reacting in alkaline solution with a hydroxy-aryl compound, the aryl nucleus of which contains not more than ten carbon atoms upon a nitro-halogenobenzene sulphochloride to produce a nitro-ha logeno sulphonic acid arylester, reacting with aqueous ammonia as superatmospheric pressure and. elevated temperature upon such nitro-halogeno sulphonic acid arylester to efl'ect the replacement of the halogen b an amino group and recovering the mtro-aminobenzene sulphonic acid arylester formed.

Ill

nitro-halogeno sulphochloride' to produce a nitro-halogeno benzene sulphonic acid phenylcster compound, reacting with aqueous ammonia at superatmospheric pressure and elevated temperature. upon such nitro-halogenobenzene sulphonic acid phenyle'ster comound to elfect replacement of the halogen y the amino group and recovering the nitro-aminobenzene sulphonic acid phenylester compound formed. I g I a 4. In processes of producing nitro-aminobenzene 'sulphonic acid phenylester compounds the steps comprising reacting with a sodium 'phenolate compound upon anitro chlorobenzene sulphochloride to produce a nitro-chlorobenzene sulphonic acid phenylester compound, reacting with ammonia upon such nitro-chlorobenzene 'sulphonic acid phenylester compound to effect the replacement of the chlorine by the amino oup and recovering the nitro-aminonzene sulphonic acid phenylester compound formed.

5. As new products nitro-aminobenzene sulphonic acid arylester compounds of the formula I NH: oa-so -on I \NO: in which R stands for an aryl radical, the aryl nucleus of which contains not more than ten carbon atoms, which are slightly colored crystalline substances, .melting undecomposed, and giving the typical reactions of aromatic primary amines. V

6. As new products nitro-aminobenzene sulphonic acid phenylester compounds of the formula in which R stands for an aryl radical of the benzene series, which are yellow" colored crystalline substances, melting undecomposed and giving the typical reactions of 50 aromatic primary amines. V 

